Electric connecter plug



June 28, 1938. A. E. GRANT ELECTRIC CONNECTER PLUG Filed Dec. 5, 1936 2 Sheets-Sheet l INVENTOR June 28, 1938. A. E. GRANT ELE CTRIC CONNECTER PLUG 2 Sheets-Sheet 2 Filed Dec. 5, 1936 INVENTOR Zber E 672272? ATTORNEY Patented :June 28, 1938 UNITED STATES PATENT OFFICE arzaoss 'nLEormo come-ran PLUG Albert E. Grant,

New York, N. Y.

12 Claims.

My invention relates to electric plug connecters of the type commonly known as heater plugs which are employed to connect current supply wires in circuit with electrical heating appliances,

suitable terminals connected to the appliances being provided for receiving the plugs.

Connecters of this character are usually provided with insulating casings of molded composition, such as hard rubber or Bakelite, and heretofore rapid deterioration of the casing adjacent the contacts has been common due-to heat gen-, erated in the appliance being conducted back through the contacts of the plug, or because of arcing between the contacts of the plug and the terminals of the appliance when the plug is being connected or disconnected or when a loose coupling is effected. To remedy this it has been proposed to construct the plug casing wholly of porcelain or other fireproof ceramic material, but such materials are highly frangible and have not met with general acceptance.

It has also been proposed to armor composition casings in metal shells. This proposal has met with considerable success, due in part to the ornamental appearance imparted to the device, but such exterior protection cannot effectively safeguard the inner insulating housing from the heat which emanates from the contacts, and frequently conceals and holds together unsafe, burnt out insulation which, if apparent, would result in the plug being promptly discarded by the user. It is an object of my invention, therefore, to provide a heater plug in which the contacts are well insulated by a bath of air contained in fireproof housing portions.

In heater plugs embodying switches, it has heretofore been common to introduce the current wires into the casing wall at the top of the plug, oppo-'- site the face thereof, and to position the switch actuator at some intermediate location. I have found that this usual arrangement is a frequent cause of annoyance because in reaching for the actuator to shut off the current it is necessary for the user to extend his hand in close proximity to the hot appliance. Also, when connected to sad irons, the current supply wires trail the butt end of the appliance and drag over the material being ironed or pressed.

It is another object of my invention, therefore, to provide an improved heater plug embodying a switch having an actuator which extends from the plug at a location as remote as possible from the face of the plug, the current supply wires extending into the housing in a plane substantially parallel with the face of the plug.

Another object is to provide a connecter plug comprising a casing formed in separable portions which may be assembled and disassembled for wiring purposes without recourse to the use of' screws or other separate fastening devices. A further object consists in providing a device of this character having but few parts compactly and conveniently arranged in combination to facilitate assembly and to obtain a sturdy and well insulated device for the purpose. Other and further objects will appear from the following specification.

Referring to the drawings which form a part of this specification:

Figure 1 is a front elevation of a connecter plug embodying my invention.

Figure 2 is an elevational view showing the right side of the device.

Figure 3 is an inverted plan view showing the face of the plug.

Figure 4 is a plan view showing the top of the plug.

Figure 5 is an elevational view of the left side of the plug and illustrates the relationship of the parts when the casing portions are separated for wiring purposes.

Figure 6 is a cross sectional view taken on line 6-4 of Figure 2.

F ure 7 is a vertical section taken on line 1-1 of Figure 6.

Figure 8 is a perspective view showing the metal shell portion of the plug housing and the ceramic face plate carried thereby.

Figure 9 is an elevational view of the switch actuator and Figure 10 is a cross section thereof taken on line Ill-l0 of Figure 9.

Figure 11 is an elevational view showing the exterior surface of the swiveling cover portion of the casing, and

Figure 12 is a cross section thereof taken on line I2-i2 of Figure 11.

Figure 13 is'an elevational view showing the interior recessed surface of the main insulating casing portion, and

Figure 14 is a verticalsectlon-thereof taken on line ll-ll of Figure 13.

The upper portion 2|! of the casing or housing is composed of molded insulating material and is formed in two parts, a main casing 2| and a swiveling cover 22 which is pivotally secured to thereof. The neck is tubular to form a wire inlet passage and is exteriorly grooved or threaded to receive the inner close wound convolutions of a helical guard 26 for the cabled current supply wires 50. v

The lower portion of the casing or housing is fireproof and composed of a metal shell 30 and a face plate 35 of porcelain or other fireproof insulating material having openings 36-36 therein to receive the standard terminal members of an electric heating appliance. The face plate is cast or molded to project into the lower end of the shell, the inwardly projecting portions thereof having integral keys 31-31 which extend through openings 3|-3| in the shell and serve to secure the face plate permanently to the shell.

The upper portion of the metal shell is flared to closely fit over the tapering walls of the upper portion of the casing and is cut away on one side at 32 to accommodate the projecting neck 25. Apertures 33-33 are formed through the shell adjacent its top for engaging the small protuberances 21-21 on the cover 22 ahd the upper edges of the shell abut a bead 28 on the upper portion of the casing which is interrupted at 25 where the wall of the cover is recessed to permit insertion of a tool under the topmargins of the shell for disengaging the shell from the protuberances 21 when it is desired to disassemble the casing portions to wire or rewire the device.

All of the interior conducting parts of the de' vice are positioned and secured in suitable recesses molded in the interior wall of the main casing 2|. A pair of similar contact clips40 and 4| are secured and connected to conductors 42 and 43, respectively, by means of eyelets 44-44. The conductor 42 carries a binding screw 45 for connecting the inner end of one of the current supply wires 50, and the conductor 43' extends into one side of a switch pocket 46 to form a switch contact 60 (see Figure 6). On the opposite side of. the pocket 9. similar switch contact 6| (see Figure 5) is formed integral with a conductor 41 which is secured to the main casing by an eyelet 48 and carries a binding terminal screw 49 for the other current supply wire 50.

Arms of an angular switch member 62 adapted to bridge the contacts 60 and GI are pivoted on the hubs 64-64 of an actuator 63 of insulating material which is pivotally mounted on the shank of the eyelet 23 and has abutton-lilre portion projecting outwardly from the top of the casing, as remotely from the face plate 35 as the dimensions of the plug will permit. Below the eyelet, the actuator is provided with a perforate depending portion 65 and a light coilspring 66 is connected between this portion of the actuator and the lower end of the bridging member 62.

This type of switch is well known, wherefore it will be readily understood that when the projecting portion of the actuator is moved toward a central position in either direction, the spring will be compressed, and when the actuator is moved passed center, the spring will instantly react to reverse the switch member and snap the actuator the balance of its movement. The pivoting movements of both the actuator and the switch member are limited by the walls of the switch pocket recess 46 formed in the main casing 2| intermediate the walls of the manual grip 24, and the exterior wall surfaces of the upper casing parts are embossed as shown to indicate the on and off positions of the switch.

From the foregoing it will be understood that one side of the circuit through the plug extends from the wire binding terminal 45 through the conductor 42 to the clip 40, and that the other side of the circuit extends from the binding terminal 49 through conductor 41 to switch contact 6| and thence across the bridging member 62 to switch contact 60 and the conductor 43 connecting with the clip 4|.

It will be noted that opposite'ends of the contact clips 40 and 4| are held in spaced relation air bath, absorbed by the metal shell and radi-v ated from its. exterior surfaces.

To disassemble the casing portions when it is desired to wire or rewire the device, the helical guard 26 is disengaged from the neck portion 25 and a tool is inserted in the recess 29 under the top margin of the shell to release the apertured portions 33 thereof from the protuberances 21; the lower portion of the casing is then removed and the cover part 22 is swung on its pivot 23 to disposed the casing portions substantially as shown in Figure 5.

To reassemble the casing, the cover part is swung back to register with the main casing, the wire guard is replaced, and the lower casing portion is drawn up until its top edge abuts the bead 28 and its perforate portions 33 snap into engagement with the protuberances 21. Itwill be noted that the pivotally connected parts forming the upper portion of the casing are held in position by the embracing lower' casing portion and the wire guard and that no bolts, screws or other independent fastening devices are required.

Thus constructed, I have found the device possesses. rugged structural characteristics, is of ornamental appearance, simple to manufacture, well insulated, and convenient to use. The side entrance of the current supply wires and the convenient central location of the switch, remote from the face of the plug, are features of the construction which will readily commend themselves to the user.

Having thus described my invention, I claim:

1. A connecter plug having an insulating upper casing portion and a fireproof lower casing portion, the upper portion comprising two sections of insulating material complementing each other to form a manual grip at the top of the plug, a

wire inlet passage at one side thereof, and a switch pocket adjacent the top of the plug interiorly of said manual grip, pivot means extending transversely of the switch pocket securing said sections together in swiveling relation, the lower portion of the casing comprising a metal shell and a face plate of ceramic insulating material carried at the lower end of the shell, said face plate having spaced socket openings therein intermediate its margins, the upper end of said shell removably embracing the lower end of the upper casing portion whereby the sections thereof are held from swiveling, spaced contact members carried by the upper portion of the casing and projecting into the lower casing portion '75 mounted for pivoting movements on the pivot means in said pocket and having an actuator extending exteriorly at the top of the plug centrally of said manual grip.

2. A connecter plug comprising a hollow lower casing portion of fireproof material having spaced socket openings in its bottom wall, a separate upper casing portion of insulating material formed in two complementary parts. secured together in swiveling relation, said upper casing portion having a wire inlet passage formed therein, wire binding terminals in the upper portion of the casing, contact members connected with said terminals and projecting from the upper portion of the easing into the lower portion thereof, said members extending in parallel spaced relation to each other in register with said socket openings, said lower casing portion embracing the parts of the upper casing portion whereby they are held from swiveling.

3. A connecter plug comprising a casing having an upper portion formed in two complementary parts of insulating material secured together ,in swiveling relation and a lower portion formed of fireproof material, said lower portion embracing the upper portion in overextending relation and preventing relative swiveling of said complementary parts and said lower casing portion being hollow to contain an air bath, a wire inlet passage formed in the upper casing portion, wire binding terminals carried within said upper portion, contact members connected with said terminals and projecting from the upper casing portion into the air bath contained in said lower portion, said contact members being disposed in parallel spaced relation to each other and in spaced relation to the side walls of said lower casing portion, said lower casing portion having apertures therein registering with the projecting ends of said contact members.

- 4. A connecter plug comprising an upper casing portion formed in two complementary parts of insulating material secured together in swiveling relation, contact members carried by said casing portion and projecting therefrom in spaced relation to each other, means carried in the said casing portion for connecting current supply wires to the contact members, a metal shell surrounding the projecting portions of the contact members in spaced relation therefrom, and a face plate of fireproof insulating material carried at the lower end of the shell, said face plate having socket openings therein in register with the projecting ends of said contact members and said shell embracing the upper casing portion in overextending relation to prevent relative swiveling of said complementary parts.

5. A connecter plug comprising an upper casing portion formed in two complementary parts of insulating material secured together in swiveling relation and having a wire inlet passage formed therein, wire binding terminals within said casing portion, contact members respectively connected with said terminals and projecting from said casing portion in parallel spaced relation to each other, a fireproof lower casing portion comprising a metal shell embracing the upper casing portion, whereby said complementary parts are .held from swiveling, and surrounding projecting portions of said contact members in spaced relation therefrom, and a faceplate of ceramic insulating material carried by the shell at its other end, said face plate having apertures therein registering with the projecting ends of said contact members.

6. A connecter plug comprising a casing having a manual grip formed on its top and a wire inlet passage at one side thereof, wire binding terminals within the casing, contact members carried by. the casing, one of said terminals being connected with one of said members. and means comprising a switch for connecting the other terminal with the other member, said switch having an actuator projecting outwardly from the casing at the top thereof centrally of said manual grip.

7. A connecter plug comprising a casing having two sections of insulating material complementing each other to form a wire inlet passage, pivot means securing said sections together in swiveling relation to each other, means for holding the sections from swiveling, wire binding terminals and contacts secured in the casing, one of said terminals being connected with one of said contactaand means comprising a switch for connecting the other terminal with the other contact, the movable parts of said switch being mounted on said pivot means.

8. A connecter plug comprising a casing having two sections of insulating material complementing each other to form a manual grip at the top of the plug, a wire inlet passage at one side thereof, and a switch pocket adjacent the top of the plug interiorly of said manual grip, pivot means extending transversely of said switch pocket securing said sections together in swiveling relationto each other, means for holding said sections from swiveling, wire binding terminals and contacts secured in the casing, one of said terminals being connected with one of said contacts, and means comprising a switch for connecting the other terminal with the other contact, said switch being mounted for pivoting movements on said pivot means in said pocket and having an actuator extending exteriorly at the top of the plug centrally of said manual grip.

9. A connecter plug having a casing comprising two sections of insulating material complementingeach other to form a tubular projecting neck portion, said sections being permanently secured together in facing engagement by means permitting relative swiveling movement and said neck portion forming a passage for leading wires into the casing, and a removable guard for said wires embracing the neck portion whereby said casing sections are held from swiveling.

10. A connecter plug having a casing comprising two sections of insulating material permanently secured together in facing engagement by means permitting relative swivelingmovement, and a removable metal shell embracing said sections whereby they are held from swiveling.

11. A connecter plug having a casing comprising two sections of insulating material complementing each other to form a tubular projecting neck portion, said sections being permanently secured together by means permitting relative swiveling movements and said neck portion forming a passage for leading wires into the casing, a removable metal shell embracing said sections and a removable guard for said wires embracing the neck portion whereby said sections are held from swiveling.

12. A connecter plug having a casing com- 

